Iberian Chiffchaff (Phylloscopus ibericus) Science Article 1
We carried out a Principal Component Analysis on 196 Iberian and Common Chiffchaffsof both sexes (live and collection specimens), characterized by seven variables derived fromwing, tarsus and bill measures. This method, complemented by colour comparison of thetaxa, led us to the following conclusions. (1)Phyllopneuste brehmii, Homeyer, 1871, is ajunior synonym ofSylvia collybita, Vieillot, 1817. The correct name for the IberianChiffchaff isPhylloscopus ibericus(Ticehurst 1937). (2)P. ibericusis itself represented bytwo subspecies: the southern formP. i. ibericus(Ticehurst 1937), and the northern form,for which we propose the nameP. i. biscayensisssp. nov.(3) The Common and IberianChiffchaffs are very distinct in the contact zone. But an overall geographical variationfollowing Bergmann’s and Allen’s rules within both taxa generates an ecomorphologicalconvergence, i.e.P. i. ibericusand the populations ofP. c. collybitafrom northern centralEurope have similar sizes. This may explain why previous authors were unable to diagnosethe two taxa on morphological criteria alone.
Marc Salomon, Jean-Francois Voisin and Joel Bried, Ibis(2003),145, 87-97